U.S. Senator Ted Cruz, the Texas Tea Party firebrand who nearly provoked the second government shutdown in a little over a year, on Tuesday apologized to his fellow Republicans for a strategy that backfired.

A Cruz spokeswoman said the senator apologized to colleagues “for inconveniencing their personal schedules” over the weekend. Cruz still believes, the spokeswoman said, that fighting to stop President Barack Obama’s new program easing deportations for millions of illegal immigrants “was critically important.”

The apology to Republican senators came at a closed-door lunch when Cruz, a possible 2016 presidential candidate, “was contrite and made an effort to explain to people he wished he hadn’t done it,” said a source familiar with the meeting.

Cruz sparked a public rebuke by fellow Republican senators. They criticized the Texan for forcing the Senate to be in session Friday night and through Saturday because he refused to allow quick passage of a $1.1 trillion bill keeping the government running beyond midnight Saturday.

Cruz’s actions inadvertently allowed Democratic leaders to advance nearly two dozen Obama nominees. These included Sarah Saldana, chosen to head the Immigration and Customs Enforcement agency. Republicans had been trying to block some of those nominations.

Some Republican senators had been privately talking up the need to punish Cruz, according to Senate Republican aides.

Among ideas were possibly denying Cruz committee assignments or “blocking him from being able to offer things,” one aide said.

Senator John Cornyn, second-ranking Senate Republican and Cruz’s fellow Texan, noted “persuasion,” rather than punishment, was the coin of the realm.

“One of the good things about being a United States senator is that any individual senator can pursue any tactics that they choose to pursue and there’s not much anybody else can do about it,” Cornyn said.

Republicans won big in Nov. 4 elections, gaining control of the Senate and expanding their majority in the House of Representatives. The party appeared to be coming together after a series of election cycles pitting Tea Party activists against mainstream Republicans.

But fissures on display last week signaled it might be complicated for the party to challenge Obama.

In September, 2013, Cruz and House conservatives collaborated to hold up a spending bill to keep the government operating. The goal that time was to gut another Obama initiative, the healthcare law known as Obamacare.

That episode resulted in a 16-day shutdown. This time, Cruz relented hours before the government was set to begin shuttering agencies.

(Reporting by Richard Cowan; Additional reporting by David Lawder; editing by Dan Grebler and David Gregorio)